1. Field of the Invention
The present invention generally relates to correction signal generating circuits and, more particularly, is directed to a raster distortion correcting signal generating circuit suitable for use in a television receiver or the like.
2. Description of the Prior Art
As a correction signal generating circuit used in a television receiver or the like, an apparatus has been proposed which generates a correcting signal such as a sawtooth wave signal or a parabolic wave signal or the like in accordance with a count value of a horizontal synchronizing (sync.) signal. However, the proposed conventional correcting signal generating circuit is constituted by analog circuits, so-called hard logics, and digital adder-subtracters.
The demand for limiting distortion has increased with the tendency of flattening and enlarging a cathode ray tube (CRT), so that a high-order deflection correcting signal has been required. However, it has been difficult to obtain sufficient accuracy when the high-order deflection correcting signal is generated by a conventional correcting signal generating circuit employing the analog circuits and digital adder-subtracters.
Further, in producing a so-called multistandardized television receiver in which the conventional correcting signal generating circuit employing the analog circuits and digital adder-subtracters is used, it is required to arrange the circuit configurations for every system or receiver. In this case, since it is further required to hold a parameter required for the adjustment for every system, a memory or the like for storing the parameter is additionally required. There is then the problem that the circuit configurations become larger.